Stratified and Buoyancy-Induced Flow in Closed Compressor Rotors

作者：Gary D. Lock, Richard W. Jackson, Mikolaj J. Pernak, Oliver J. Pountney, Carl M. Sangan, J. Michael Owen, Hui Tang, James A. Scobie · 发表于：Journal of Turbomachinery · 年份：2022 · DOI：10.1115/1.4055448 · 被引用次数：14 · 研究领域：Turbomachinery Performance and Optimization、Heat Transfer Mechanisms、Fluid Dynamics and Turbulent Flows

Abstract The radial growth of compressor discs is strongly influenced by conjugate heat transfer between conduction in the co-rotating discs and buoyancy-driven convection in the rotating fluid core between the discs. An accurate prediction of metal temperatures of these discs is an important issue in thermo-mechanical design, where blade-tip clearances must be controlled carefully to ensure safety and efficiency under all operating conditions. This paper presents an experimental study of the fluid dynamics and heat transfer in a closed rotating cavity, comparing results with theoretical models and introducing a new compressibility parameter χ. At large values of χ, where compressibility effects are significant, the air temperature approaches that of the shroud; such conditions suppress buoyancy effects and the flow in the rotating cavity becomes stratified, with convection replaced by conduction inside the fluid core. There are important practical consequences of stratification with significant differences in temperature distributions and stresses inside compressor discs. The influence of χ is also shown on the radial temperature distributions for the discs and on the shroud heat transfer correlations, which are compared qualitatively with previously published data collected where the effects of compressibility are relatively small. The experiments reveal that there is a critical value of χ where the convective heat flux to the shroud is zero. The radial distribution of disc...